Spruce bog pirates in northeastern Minnesota have been cashing in on suburban cravings for holiday greenery by illegally clipping thousands of tree tops and selling them on the black market.

Conservation officers for the Department of Natural Resources, aided by foresters, police, deputies and state troopers, are scrambling to thwart the trade during its pre-Christmas peak. Suspected thieves have been busted with at least 15,000 pieces of the wild-grown contraband in the DNR’s northeast region since late September.

Capt. Shelly Patten, DNR enforcement manager for the region, said it’s not a new problem. But the abuse is spiking to a new level this fall because demand for the decorative material is strong and COVID-19 has eliminated the supply of more than 1 million tree tops normally exported to the United States from Ontario.

“We’ve had a lot of spruce top cases the last couple of weeks,’’ Patten said. “There’s thieving in the woods.’’

Conservation officer Shane Zavodnik, who patrols the Cook area, said he’s busy with ongoing investigations. Some fly-by-night operators have been aggressive enough in their pursuit of pine to gross $1,000 a day — the kind of money that attracts others, he said.

The violators clip spruce trees without a permit and sell the 2- to 4-foot tops to unlicensed, back-channel buyers who offer cash.

“It’s blown up out of proportion more than we’ve ever expected,’’ Zavodnik said. “It just seems like this year is the pinnacle of years.’’

With several weeks remaining in the 2020 harvest season, the DNR has increased surveillance of public land to disrupt the illicit, after-dark cutting. Private landowners also have been victimized. In areas such as Koochiching County, where massive spruce bogs are common, cutters can work in remote areas.

Minnesota is a national leader in the holiday greens industry with the DNR estimating annual sales of more than $23 million. But Sean Timonen, owner of St. Paul-based Black Spruce Holdings LLC, said the market has grown beyond those expectations.

In an interview this week, he welcomed the DNR’s crackdown but emphasized that legitimate companies like his dominate the field.

“There is some theft involved … but it’s de minimis,’’ said Timonen, whose company is closing in on annual production of 1 million spruce tops a year.

He said the mainstream buyers of Minnesota’s spruce tops, balsam boughs and birch poles include nurseries, floral shops, landscape companies, retail chains and big-box stores all the way to the East Coast. They buy from reputable suppliers who tread carefully in the woods to keep the resource renewable. When properly cut, spruce tops and balsam boughs regenerate.

More than a decade ago, conifer limbs for wreath-making were the industry’s cornerstone. But spruce tops have taken over, filling winter-themed planters on front porches and making for tabletop trees.

In 2019, the state Legislature updated the law that required buyers of balsam boughs to obtain a DNR license. The new law applies more broadly to “decorative materials buyers.’’

If you purchase more than 100 pounds of greenery from a harvester, you’re required to carry a license and keep the documents that describe exactly where the material came from, who cut it and what consent was given by the forest authority.

Current DNR license data support the notion that the market is hot in 2020. As of Oct. 10, the agency sold 76 decorative materials buyer’s licenses, 52 % greater than the six-year average for the old buyer’s license.

On the side of harvesting, DNR has issued permits since July for the cutting of 677,000 conifer pieces. That’s almost double the amount permitted for harvest two years ago and it doesn’t include spruce tops and balsam boughs cut on county land, tribal land, private land and Minnesota’s two federal forests. The various government permits restrict harvesters to specific areas.

For state land, permits of varying size are offered at auction. Baseline prices are 27 cents for each 2- to 4-foot piece and 36 cents for each 4- to 6-foot piece. Once harvested, the spruce tops have been fetching at least a dollar a piece on the street, a DNR official said.

Lt. Brent Speldrich, a DNR enforcement supervisor in the northeast region, said it’s clear that Minnesota’s black spruce swamps are getting hit hard this year. More than once this fall, officers have confiscated as many as 3,500 spruce tops from suspected pirates. In some cases, the thieves are stealing from roadside stacks left by legitimate cutters who are deep in the woods.

“They’re not afraid to go and grab it,’’ he said.

Speldrich, Zavodnik and Patten said the DNR’s enforcement campaign this year is heavy on education for violators — cutters as well as buyers.

“We want this to be a learning lesson and not a financial burden,’’ Zavodnik said. “We’re trying to get the different cutters and buyers on our side.’’